Management Issues


Water quality conditions (flow, temperature, and dissolved oxygen) in both the estuary and creeks during the late summer and early fall are limiting salmonid health and productivity.

Fine sediment is contributed by eroding stream banks, poorly maintained roads, and culverts.

Instream habitat could be improved by increasing structure and removing barriers.

Findings Related to Issues

Water quality conditions (flow, temperature, and dissolved oxygen) in both the estuary and creeks during the late summer and early fall are limiting salmonid health and productivity:

Low stream flow in the late summer and fall are exacerbated by water extraction and diversions in the Inland Subbasin;

Water temperatures and dissolved oxygen in the mainstem estuary may be unsuitable for salmonids;

Dissolved oxygen levels may be unsuitable in the North Fork Albion.

Fine sediment is contributed by eroding stream banks, poorly maintained roads, and culverts:

High road density throughout the watershed, both current and legacy;

Excess fine sediment generated by surface erosion from residential winter road use;

Sediment from poorly maintained and undersized County road culverts;

Levels of fine sediment in some areas (<6.4mm) may impact instream conditions;

Instream substrate particle size (D50) is generally small throughout the basin;

Permeability samples at the South Fork Albion sample site were low;

There is evidence of stream bank erosion caused by livestock grazing within the riparian zone in some areas of the basin.

Instream habitat could be improved by increasing structure and removing barriers:

Large Woody Debris (LWD) recruitment potential is generally poor;

There is a shortage of instream LWD in most stream reaches;

Inadequate spawning habitat due to limited recruitment, sorting, and retention of cobble size substrate;

Some fish passage barriers related to Mendocino County road stream crossings.

Recommendations

Flow and Water Quality Activities

Conserve water during the late summer and early fall low flow periods.

Use water storage and catchment systems to collect rainwater during the mid-late winter months.

Develop and implement a water quality monitoring program focused on temperature and dissolved oxygen.

Erosion and Sediment

Decommission abandoned roads and rock roads and/or take other measures to decrease fine sediment contribution.

Restrict access to unpaved roads during the winter months.

Revegetate stream banks to reduce erosion.

Use exclusion fencing where there is evidence of stream bank erosion caused by grazing livestock.

Riparian and Instream Habitat

Add Large Woody Debris to increase shelter/cover and pool depth.

Add gravel and cobble to increase available spawning substrate if the additional structure fail to retain sufficient amounts.

Support fish passage improvements.

Education, Research, and Monitoring

Support local efforts to monitor water quality, water conservation, and instream habitat conditions in the estuary and streams.

Conduct salmonid surveys to estimate population and to help evaluate the effectiveness of habitat restoration.